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The southern portion of the Machete Ridge rock formation and access trails are closed to all climbing and off-trail hiking.

Raptor Monitoring Update for July 2015

posted: July 11, 2015

Hey Everyone -

Here is a final update on raptor activity at Pinnacles National Park as the breeding season comes to a close.

Prairie falcons (PRFA) and peregrine falcons (PEFA) have raised and fledged young from successful nests. Prairie falcon productivity was lower in 2015 compared to 29-year averages, but overall falcon productivity was supplemented by successful nest efforts of two peregrine falcon nests that produced fledglings.

The following territories were unoccupied, with no prairie falcons observed within them:

Pig Canyon

North Balconies

Scout Peak

Western Front

Discovery Wall

Pipsqueak Pinnacles

Frog / Hand

Piedras Bonitas / Gargoyle / Prescribed Burn Cliffs

Tugboat

D. Soto Canyon

Guard Rock

Rocks West of Chalone Housing

Mating Rocks / Tugboat

North Wilderness Rock

South Wilderness Rock

As noted above, PRFA productivity this season was lower than the 29-year averages for the raptor monitoring program. Eight PRFA pairs attempted to nest, and 5 nests successfully fledged 19 young, compared to 29-year averages of 11.9 nesting pairs, 10.0 successful nests, and 27.3 fledglings. Exact causes of the lower productivity this season are unknown, but likely factors include nest predation and lower prey availability due to the ongoing drought conditions. The two peregrine falcon nests together fledged a total of 6 fledglings, our highest annual fledge count for PEFA since breeding pairs returned to the park in 2004.

Please note that all climbing and hiking advisories have been lifted as of July 4th. Climbers and hikers generally did an excellent job of adhering to advisories and allowing falcons to nest in chosen territories throughout the park. I definitely appreciate the support!

In addition to PRFA and PEFA, twenty other raptor nests were confirmed this year. These included:

7 red-tailed hawk nests

3 red-shouldered hawk nests

4 American kestrel nests

2 Cooper's hawk nests.

A highlight for 2015 was the documentation of 4 long-eared owl nests, the highest number of nests recorded for this species of concern in a single year.

Thank you to all the staff who have continued to provide me with raptor observations; every detail on raptor behavior helps to provide a more complete picture of raptor breeding at the park. If anyone on staff wishes to report raptor observations, I would greatly appreciate it if you please fill out a wildlife observation card, and deposit it in my box in the RRM Office.